The series was debuted on 29 October 2017 and was simulcast on BBC One, BBC One HD and BBC Earth, making it the first natural history series to premiere on the same day in the United Kingdom, Nordic regions, Europe and in Asia.

In the United States, the series premiered on Saturday, January 20, 2018, at 9 PM as part of a five-network simulcast on BBC America, AMC, IFC, Sundance, and WE tv. Subsequent episodes aired on successive Saturdays on BBC America.

The series was announced by the BBC in 2013 with the working title Oceans, but the title was later changed to Blue Planet II as it revealed on 19 February 2017.[3][4] Filming took place over a course of more than four years; involving 125 expeditions across 39 countries and produced more than 6,000 hours of underwater dive footage from over an estimated 4,000 dives.[5]

Composer Hans Zimmer returned to score the series.[2] In September 2017, the BBC announced that the English rock band Radiohead had collaborated with Zimmer to record a new version of "Bloom", a song from their 2011 album The King of Limbs.[6] The new track, "(ocean) Bloom", was recorded alongside the BBC Concert Orchestra. In a press release, Radiohead singer Thom Yorke said: "'Bloom' was inspired by the original Blue Planet series so it's great to be able to come full circle with the song."[6]

The premiere of the series took place at Bristol's Cinema de Lux on 11 October 2017, with special guest appearance by Attenborough alongside with the producers and wildlife experts. Bristol has been the global home of BBC's Natural History programme making for the past 60 years.[7][8][9] The series was first broadcast on 29 October 2017 (from 20:00 GMT to 21:00 GMT) on BBC One and BBC One HD.[10] The first six episodes included a 10-minute making-of documentary called Into the Blue.[11] The previous week's episode was repeated in an earlier time slot the following Sunday. The series was critically acclaimed[12] and gained the highest UK viewing figure for 2017, 14.1 million.[13]

The series is set to broadcast internationally on BBC Earth channel, and also commercial television channels in various countries, besides.[14] The series debuted in Nordic regions and other European countries on 29 October 2017.[16][17][18][19][20] In Asia, the series began to premiere on each early Monday (from 04:05 SGT to 05:05 SGT) starting from 30 October 2017,[21][22][23] the episode was then repeated on following each Tuesday evening (from 20:00 SGT).[22][23][24] In Poland, it premiered on 16 November 2017.[25] As for South Africa, it aired from 4 February 2018.[26]

In the Netherlands, the series is airing on the Dutch channel NPO 1, with episodes airing each Thursday from 28 December 2017.[31] In Belgium, it will air on the Flemish channel Canvas, with episodes airing each Saturday starting from 2 January 2018.[32]

The series is airing in Canada and the United States on 20 January 2018.[33][34][35] In Canada, it will broadcast with a three-network simulcast across BBC Earth, Cottage Life and T+E channel.[33] In the United States, the series will premier the first episode – with a five-network simulcast across BBC America, AMC, IFC, WE tv and Sundance TV,[34][35] while the remaining episodes will continue to be air every Saturday on BBC America. It is also available on BBCAmerica.com and the BBCA app.[36]

Examining the role of human anthropogenic activity on the oceans. Microplastics and pollution are an increasing problem for the world's seas, threatening the lives of marine life and ultimately affecting the ecosystem. Can humans reverse their activity to protect the seas and the wildlife that inhabit it?[51]

The programme has been credited with raising awareness of plastic pollution both domestically and internationally, an influence dubbed the 'Blue Planet effect'.[59]

Following the programme's airing in the UK, the BBC announced its intention to completely ban single-use plastics within its organisation by 2020.[60] In April 2018, in response to growing public support directly linked to Blue Planet II, the British government announced it is considering a national ban on single-use plastic products.[61] It was also reported that Queen Elizabeth II's decision to ban plastic bottles and straws across the Royal estates was in part a response to the documentary.[62]

British universities such as the University of Southampton noticed a sudden increase in applications for marine biology courses following the programme's airing, which was again attributed to the 'Blue Planet effect'.[63]

It was reported that the number of people in China simultaneously streaming Blue Planet II (approximately 80 million) had a noticeable impact upon internet speeds within the country.[64] The popularity of the documentary in China was cited as partly the reason British prime minister Theresa May gave Chinese president Xi Jinping a Blue Planet II box set signed by David Attenborough. It was also symbolic of a joint plan to tackle plastic pollution and the illegal wildlife trade, announced by British officials during Xi's 2018 visit.[65][66][67]

The series was released as a three-disc DVD set[69] as well as a standard Blu-ray set[70] on 27 November 2017, and as a six-disc 4K UHD Blu-ray + Blu-ray set[71] on 15 January 2018. It is distributed by BBC Worldwide in the UK.

In the US and Canada, the DVD,[72][73] Blu-ray[74][75] and 4K UHD Blu Ray[76][77] sets were released on 6 March 2018 and distributed by BBC Worldwide Americas.

An accompanying hardback book was written by James Honeyborne and Mark Brownlow, with foreword by David Attenborough. It was published by BBC Books (ISBN978-1849909679). The book was released on 19 October 2017 in the UK[78][79] and on 1 January 2018 in the US.[80]

The musical score and songs featured in the series were composed by Hans Zimmer, Jacob Shea and David Fleming for Bleeding Fingers Music. A digital soundtrack was released on 29 October 2017, while a single physical disc was released on 1 December 2017 in the UK.[82][83][84][85]